Improvement in blackboards



H. W. EASTMAN.

Blackboard.

No. 204,011 Patented IVlay 21 ,m mhL. hohl@ MEHR .1w.., .lfwfd *YHATTUBNEYS. 1

UNITED STATES PATENT OTFI HENRY W. EASTMAN, OF BALTIMORE, MARYLAND,ASSIGN OR TO HIMSELF AND WILLIAMJ. C. DULANY, OF SAME PLACE.

f||v|PRov|aM ENT IN LAcKLao/imns;V

Specification forming part of Letters Patent No. 204,011, dated May 21,1878; application filed March 16, 1878.

'To all whom t may concerm.

Be it known that I, HENRY W. EASTMAN, of Baltimore city, State ofMaryland, have invented a new and useful Improvement in Blackboard; andI do hereby declare that the following is a full, clear, and exactdescription of the same.

The invention relates to an improvement in that class of blackboards forschool use in which the blackboard proper is suspended in a verticalframe in such manner that it may be adjusted at various heights, forconvenience of use and observation.

According to my' invention, the blackboard is pivoted in its sliding`frame, which is balanced by a vertically-sliding frame, adapted forholding printed alphabetical tablets or arithmetica-l plates or tablets.The tabletholding frame may be so adjusted as to hold the pivotedblackboard in position-that is to say, prevent it turning on its pivots.

In the accompanying drawing, forming part of this specification, Figurelis afront elevation, and Fig. 2 a vertical section, (one of thehingedtablet-holdingframesbeingrepresented swung open.)

A indicates the blackboard, B the tabletholders, and O the frame, inwhich said parts A B are arranged to slide in parallel vertical planes.

The side bars of the frame C are grooved to receive projections or ribson the ends of the blackboard and tablet-holder, so that the two latterare guided vertically Vas they are raised and lowered. The tablet-holderacts as a counterbalance for the blackboard, being connected thereto bymeans of cords passing over pulleys D D located at the top of the mainframe C.

When the blackboard is drawn down the tablet-holder is necessarilyraised, and when the tablet-holder is drawn down 'the blackboard isnecessarily raised, one balancing the other, and either remainingstationary in any adjustment. Hence the blackboard may be easily drawndown when it is desired to write or draw thereon, and raised againtovexhibit the work. llhe tablet-holder may be similarly operated forthe purpose of placing new cards or tablets in its rabbeted frame, andthen exposing them plainly to view. When the cards or tablets are inplace they are secured by a frame or frames that are hinged to the sidebars of the holder B.

The blackboard proper is pivoted centrally at top and bottom a b, sothat it may be easily reversed when it is desired to bring the oppositeside to the front.

When the tablet-holder C is lowered it prevents the blackboard beingreversed or turned on its pivots, las shown in Fig. 2, since the formeris then directly behind the latter, and

in contact with it, or nearly so. Thus thel blackboard is keptstationary on its pivots, or prevented from turning thereon when thetablet-holder is lowered into position behindit, but may be quicklyreversed when the tabletholder is raised.

In this manner I secure the advantages attending the use of the commonpivoted reversible blackboard, and at the same time adapt the board tobe adjusted vertically with ease and rapidity, and to be held fixed onits pivf ots'by the same means-to wit, the tabletholder-by which-it iscounterbalanced.

As above intimated, I am aware that a vertically-sliding blackboardadapted tobe reversed is not new.

I am also aware that a blackboard pivoted in its frame for reversal, butnot capable of

